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Trends in Utility Green Pricing Programs (2003)

Description: Utilities first began offering consumers a choice of purchasing electricity generated from renewable energy sources in the early 1990s. Since then, the number of U.S. utilities offering green pricing programs has steadily grown. Today, more than 500 utilities in regulated electricity markets--or about 16% of all utilities nationally--offer their customers green power options. Because some of these utilities offer programs in conjunction with cooperative associations or other public power entities, the number of distinct programs is slightly more than 100. Through these programs, more than 33 million customers spanning 34 states have the ability to purchase renewable energy to meet some portion or all of their electricity needs, or make contributions to support the development of renewable energy resources. Typically, customers must pay a premium above standard electricity rates for this service. This report presents year-end 2003 data on utility green pricing programs, and examines trends in consumer response and program implementation over time. The data provided in this report can be used by utilities as benchmarks by which to gauge the success of their green power programs.
Date: September 1, 2004
Creator: Bird, L. & Cardinal, K.

Turbine Research Program Cold Weather Turbine Project: Period of Performance May 27, 1999 -- March 31, 2004

Description: Northern Power Systems completed the Cold Weather Turbine (CWT) project, which was funded by the National Renewable Energy Laboratory (NREL), under subcontract XAT-9-29200-01. The project's primary goal is to develop a 100-kW wind turbine suited for deployment in remote villages in cold regions. The contract required testing and certification of the turbine to the International Electrotechnical Commission (IEC) 61400-1 international standard through Underwriters Laboratories (UL). The contract also required Northern Power Systems to study design considerations for operation in extreme cold (-80F at the South Pole, for example). The design was based on the successful proof of concept (POC) turbine (developed under NREL and NASA contracts), considered the prototype turbine that would be refined and manufactured to serve villages in cold regions around the world.
Date: August 1, 2004
Creator: Lynch, J.; Bywaters, G.; Costin, D.; Hoskins, S.; Mattila, P. & Stowell, J.

Uncertainty Analysis for Broadband Solar Radiometric Instrumentation Calibrations and Measurements: An Update; Preprint

Description: The measurement of broadband solar radiation has grown in importance since the advent of solar renewable energy technologies in the 1970's, and the concern about the Earth's radiation balance related to climate change in the 1990's. In parallel, standardized methods of uncertainty analysis and reporting have been developed. Historical and updated uncertainties are based on the current international standardized uncertainty analysis method. Despite the fact that new and sometimes overlooked sources of uncertainty have been identified over the period 1988 to 2004, uncertainty in broadband solar radiometric instrumentation remains at 3% to 5% for pyranometers, and 2% to 3% for pyrheliometers. Improvements in characterizing correction functions for radiometer data may reduce total uncertainty. We analyze the theoretical standardized uncertainty sensitivity coefficients for the instrumentation calibration measurement equation and highlight the single parameter (thermal offset voltages), which contributes the most to the observed calibration responsivities.
Date: April 1, 2004
Creator: Myers, D. R.; Reda, I. M.; Wilcox, S. M. & Stoffel, T. L.

Unusual Capacitance Emission Transients in CIGS Caused by Large Defect Entropy Changes

Description: Capacitance transient data from bias-pulse experiments on CdS/CIGS solar cells show an unusual behavior at high temperatures. Above 350 K, a minority-carrier trap, with a larger activation energy than a majority-carrier trap, emits faster than the lower activation-energy minority trap. A simple enthalpy model for trap emission cannot explain this counterintuitive behavior; but the more complete Gibbs free-energy model that includes entropy can explain it. We show that entropy plays a major role in carrier emission from traps in CIGS.
Date: February 1, 2005
Creator: Young, D. L.; Ramanathan, K. & Crandall, R. S.

Van Geet Off-Grid Home: An Integrated Approach to Energy Savings

Description: The Van Geet home near Denver, Colorado, exemplifies the effectiveness of coupling energy conservation measures with renewable energy utilization in a modern residence. The remote location, with no utility connections available, and the owner's interest in renewable energy motivated the ambitious design. This design attracted the interest of the Building America (BA) program and was studied as a research home. As a result, the BA program provided energy engineering throughout the design, construction, and performance evaluation phases. The American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) also recognized the success of this project by awarding it an ASHRAE Technology Award in 2001.
Date: August 1, 2004
Creator: Barley, C. D.; Torcellini, P. & Van Geet, O.

Las Vegas Serves up Biodiesel for Local Schools

Description: This 2-page Clean Cities fact sheet describes the use of biodiesel as a fuel source in buses by the Clark County School District, located in Las Vegas, NV. It includes information on the history of the program, along with contact information for the local Clean Cities Coordinator and Clark County School District.
Date: April 1, 2004

Whitehead Biomedical Research Building at Emory University, Atlanta, Georgia; Laboratories for the 21st Century Case Studies

Description: This case study of the Whitehead Biomedical Research Building is one in series of case studies for ''Laboratories for the 21st Century,'' a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy Federal Energy Management Program. It is intended for those who plan to design and construct public and private-sector laboratory buildings.
Date: April 1, 2005

Wind-Battery-Hydrogen Integration Study

Description: A study was performed to examine the possibility of using batteries and Hydrogen systems to add dispatchability to wind power. A second study examined the production of hydrogen by wind power for sale into a fuels market. Calendar year 2002 load information from the California ISO was combined with 2002 generated wind power from the Lake Benton wind farm in Minnesota. Control systems were developed and optimized, and grid operation for 2002 was simulated with batteries, electrolyzers, fuel cells or other elements. This report presents the results of the two studies.
Date: May 1, 2004
Creator: Fingersh, L. J.

Trombe Walls in Low-Energy Buildings: Practical Experiences; Preprint

Description: Low-energy buildings today improve on passive solar design by incorporating a thermal storage and delivery system called a Trombe wall. Trombe walls were integrated into the envelope of a recently completed Visitor Center at Zion National Park and a site entrance building at the National Wind Technology Center located at the National Renewable Energy Laboratory. NREL helped to design these commercial buildings to minimize energy consumption, using Trombe walls as an integral part of their design.
Date: July 1, 2004
Creator: Torcellini, P. & Pless, S.

Using the HOMER Model in Air Quality Analysis

Description: HOMER, the micropower optimization model created by the National Renewable Energy Laboratory (NREL), helps design and analyze off-grid and grid-connected power systems. One of HOMER's newest features is its enhanced ability to estimate air emissions for different micropower systems.
Date: August 1, 2004

VAR Support from Distributed Wind Energy Resources: Preprint

Description: As the size and quantity of wind farms and other distributed generation facilities increase, especially in relation to local grids, the importance of a reactive power compensator or VAR support from these facilities becomes more significant. Poorly done, it can result in cycling or inadequate VAR support, and the local grid could experience excessive voltage regulation and, ultimately, instability. Improved wind turbine and distributed generation power control technologies are creating VAR support capabilities that can be used to enhance the voltage regulation and stability of local grids. Locating VAR support near the point of consumption, reducing step size, and making the control active all improve the performance of the grid. This paper presents and discusses alternatives for improving the integration of VAR support from distributed generation facilities such as wind farms. We also examine the relative effectiveness of distributed VAR support on the local grid and how it can b e integrated with the VAR support of the grid operator.
Date: July 1, 2004
Creator: Romanowitz, H.; Muljadi, E.; Butterfield, C. P. & Yinger, R.

Weyerhaeuser Company: Longview Mill Conducts Energy and Water Assessment that Finds Potential for $3.1 Million in Annual Savings

Description: Weyerhaeuser completed a plant-wide energy assessment at its pulp and paper manufacturing facility in Longview, Washington, in 2002. The assessment identified nine projects for improving energy efficiency and reducing water consumption. Implementing these projects will save an estimated $3.1 million annually in natural gas costs. These measures will also reduce site water consumption by 3,600 gallons per minute. The estimated cost of these improvements is estimated at $5 million to $11 million. Aside from the nine projects discussed above, the assessment team also identified the potential to increase onsite power generation by up to 15 megawatts.
Date: June 1, 2004

Development of an In-Line Minority-Carrier Lifetime Monitoring Tool for Process Control during Fabrication of Crystalline Silicon Solar Cells: Annual Subcontract Report, June 2003 (Revised)

Description: Under the PV Manufacturing R&D subcontract''Development of an In-Line, Minority-Carrier Lifetime Monitoring Tool for Process Control during Fabrication of Crystalline Silicon Solar Cells'', Sinton Consulting developed prototypes for several new instruments for use in the manufacture of silicon solar cells. These instruments are based on two families of R&D instruments that were previously available, an illumination vs. open-circuit-voltage technique and the quasi-steady state RF photoconductance technique for measuring minority-carrier lifetime. Compared to the previous instruments, the new prototypes are about 20 times faster per measurement, and have automated data analysis that does not require user intervention even when confronted by challenging cases. For example, un-passivated multi-crystalline wafers with large variations in lifetime and trapping behavior can be measured sequentially without error. Five instruments have been prototyped in this project to date, including a block tester for evaluating cast or HEM silicon blocks, a CZ ingot tester, an FZ boule tester for use with long-lifetime silicon, and an in-line sample head for measuring wafers. The CZ ingot tester and the FZ boule tester are already being used within industry and there is interest in the other prototypes. For each instrument, substantial R&D work was required in developing the device physics and analysis as well as for the hardware. This work has been documented in a series of application notes and conference publications, and will result in significant improvements for both the R&D and the industrial types of instruments.
Date: April 1, 2004
Creator: Sinton, R. A.